Changes in urban stream water quality in Auckland, Wellington, and Christchurch, New Zealand
By indicator and trend, from 2008 to 2015, number of sites
| Stream water quality indicator | Concentration trend | Number of sites |
|---|---|---|
| Copper | decrease | 2 |
| Copper | increase | 0 |
| Copper | not confident | 12 |
| Dissolved reactive phosphorus | decrease | 30 |
| Dissolved reactive phosphorus | increase | 4 |
| Dissolved reactive phosphorus | not confident | 17 |
| Zinc | decrease | 6 |
| Zinc | increase | 2 |
| Zinc | not confident | 6 |
| E.coli | decrease | 3 |
| E.coli | increase | 19 |
| E.coli | not confident | 29 |
| Ammoniacal nitrogen | decrease | 11 |
| Ammoniacal nitrogen | increase | 4 |
| Ammoniacal nitrogen | not confident | 23 |
| Nitrate-nitrogen | decrease | 23 |
| Nitrate-nitrogen | increase | 6 |
| Nitrate-nitrogen | not confident | 20 |
Definitions
Zinc and copper are heavy metals that can accumulate in sediments, shellfish, and other aquatic organisms. Metals can reach toxic levels in organisms making them unsafe to eat and can be toxic to aquatic life.
Nitrogen and phosphorus are nutrients that can cause excessive algal growth. Ammonical nitrogen and nitrate-nitrogen can be toxic to aquatic life if concentrations in streams are high enough.
E.coli is an indicator of disease-causing organisms, which may affect human health and recreational values in streams.
Data calculation/treatment
Figure.NZ undertook simple calculations on the original csv data (sum by outcome and indicator) to mirror the analysis undertaken for the Environmental Reporting Series (see http://stats.govt.nz/browse_for_stats/environment/environmental-reporting-series/environmental-indicators/Home/Fresh%20water/urban-stream-water-quality.aspx Figure 1)
Data provided by
Dataset name
Environmental Reporting: Urban stream water quality trends 2008–2015
Webpage:
https://data.mfe.govt.nz/table/3598-urban-stream-water-quality-trends-200815
How to find the data
At URL provided, select 'Export' from the top right of the screen, and then 'Create Export'. You will have to register to download this dataset.
Import & extraction details
File as imported: Environmental Reporting: Urban stream water quality trends 2008–2015
From the dataset Environmental Reporting: Urban stream water quality trends 2008–2015, this data was extracted:
- Sheet: Sheet1
- Range:
B6:D11 - Provided: 18 data points
This data forms the table Environment - Urban stream water quality trends at monitored sited in Auckland, Wellington, and Christchurch 2008–2015.
Dataset originally released on:
April 24, 2017
Method of collection/Data provider
Auckland Council, Greater Wellington Regional Council, and Christchurch City Council collect urban stream water samples monthly at fixed locations and send them to a laboratory for chemical and bacterial analysis.